In some high-speed and high-precision signal processing and conversion circuits, it needs some switches to implement the process in which the analog signal is acquired and transmitted. A switch control circuit is configured to control on/off of these switches. Under the premise that the characteristics of the transistors that constitute the switch are constant, the higher the voltage driving the switch is, the smaller the on-resistance of the switch is. The on-resistance is reduced, so that the speed at which the analog signal passes through the switch can be accelerated and the distortion of the analog signal can be reduced. The conventional switch control circuit can boost the driving voltage. However, when the system supply voltage is too high or the sampled analog signal has a large voltage range, it is easily caused that the driving voltage on the sampling switch is too high, so as to result in the risk that the sampling switch is broken down, which reduces reliability of the circuit.